The invention relates to a method for controlling a vehicle lifting device, wherein at least two—preferably moveable—lifting columns are provided, which are controlled wirelessly, such that when a switch is activated in the sense of raising or lowering the lifting device, a corresponding signal is transmitted wirelessly to the lifting columns, and such that additional signals, which are representative for the individual lifting movements, are transmitted to a control device and for unacceptably high differences in motion among individual lifting columns, the normal operation is stopped.
Such lifting devices with wireless control are known, for example, from U.S. Pat. Nos. 6,634,461 and 7,014,012. Here, each lifting column is provided with its own control device, such that the lifting columns communicate among each other, in order to coordinate the lifting movements.
The sense and purpose of the wireless signal transmission consists in that no electrical cables must be laid between the lifting columns and that the lifting columns can be moved to a different location in the workshop in a very simple manner without detaching them from electrical or hydraulic connections. Therefore, not only is it possible to use the lifting columns equally for passenger cars and also for large trucks, but they can also be moved to the side after use, for example, so that the workshop area becomes free for other tasks.
So that the operation of the lifting columns is not disrupted by external signals, it is already known for security reasons to code the control signals individually. Therefore, only the control signals recognized as correct are accepted at the lifting columns and used for triggering a lifting movement or for stopping the lifting movement.